The present invention relates to structures for human accommodation, more particularly to construction or architecture of such structures, terrestrial or aquatic, having one or more relatively large interior openings.
Certain types of marine vessels, such as container ships, have large interior openings (in marine terminology, "hatches") which permit and facilitate access, e.g., to cargo, interior spaces and modular payloads. Conventionally, cargo hatches are large rectangular openings in the deck which allow for easy loading and discharge of cargo; typically, such rectangular openings replace a substantial portion of the deck area, thereby leaving a significantly reduced deck structure.
This reduction of the deck structure in conventionally constructed ships can present structural difficulties. In effect to some degree, a conventionally constructed cargo ship with large hatch openings has an "open" top and is thus analogous to a shoe box; subjection to strains of the conventionally constructed ship which has large openings can cause the ship to behave in a similar manner as would a shoe box under similar circumstances.
In particular, if the conventionally constructed ship having large hatches is subjected to a twisting load, the structurally reduced deck has reduced rigidity and hence reduced ability to control the deflections from this twist. Such deflections can have adverse effects; for example, large stresses at the hatch corners can lead to structural failure.
Conventional approaches to addressing these concerns have involved the utilization of structural reinforcement. One methodology has included increasing the thickness of the plating in the deck structure. Another methodology has included the addition of longitudinal box girders to increase the torsional and longitudinal rigidity of the ship hull.